Developments in Atmosphere Revitalization Modeling and Simulation

Abstract

"NASA's Advanced Exploration Systems (AES) program is pioneering new approaches for rapidly developing prototype systems, demonstrating key capabilities, and validating operational concepts for future human missions beyond Earth orbit" (NASA 2012). These forays beyond the confines of earth's gravity will place unprecedented demands on launch systems. They must not only blast out of earth's gravity well as during the Apollo moon missions, but also launch the supplies needed to sustain a crew over longer periods for exploration missions beyond earth's moon. Thus all spacecraft systems, including those for the separation of metabolic carbon dioxide and water from a crewed vehicle, must be minimized with respect to mass, power, and volume. Emphasis is also placed on system robustness both to minimize replacement parts and ensure crew safety when a quick return to earth is not possible. Current efforts are focused on improving the current state-of-the-art systems utilizing fixed beds of sorbent pellets by evaluating structured sorbents, seeking more robust pelletized sorbents, and examining alternate bed configurations to improve system efficiency and reliability. These development efforts combine testing of sub-scale systems and multi-physics computer simulations to evaluate candidate approaches, select the best performing options, and optimize the configuration of the selected approach, which is then implemented in a full-scale integrated atmosphere revitalization test. This paper describes the development of atmosphere revitalization models and simulations. A companion paper discusses the hardware design and sorbent screening and characterization effort in support of the Atmosphere Revitalization Recovery and Environmental Monitoring (ARREM) project within the AES program. I. Nomenclature

Development of Carbon Dioxide Removal Systems for Advanced Exploration Systems 2012-2013

“…The development of CO 2 removal and associated air-drying models and simulations under the ARREM project is discussed in companion papers. 3 …”

Hydrogen-powered Electrochemically-driven CO2 Removal from Air Containing 400 to 5000 ppm CO2

“…In the CDRA, the solid adsorbent beds are accompanied by a substantial footprint associated with the pressureswing regeneration system and air pretreatment and post-treatment, meaning a significant portion of the equipment will not be required if replaced by the EDCS system. 77 When both solid adsorbent beds in the CDRA are online (meaning no regeneration and no long-term operation), the CDRA can maintain a cabin air concentration of 3,000 ppm CO 2 . In order to reach the lower CO 2 concentration target, the CDRA will require the addition of new beds and the associated controls or a substantial improvement in the adsorbent performance.…”